#include<iostream>
#include<future>

int Add(int a,int b){
    return a+b;
}
int main(){
    std::packaged_task<int(int,int)> task(Add);
    std::future<int> fu = task.get_future();
    task(1,2);
    std::cout<<fu.get()<<std::endl;
    return 0;
}